1. Field of the Invention
The present invention relates to a light generating device capable of improving light uniformity, a display apparatus having the light generating device, and a method of driving the light generating device.
2. Description of the Related Art
In general, as a backlight unit that supplies light to a display panel, a cold cathode fluorescent lamp (CCFL) and a light emitting diode (LED) are widely used.
In order to improve display quality, a display apparatus to which the LED is applied adopts various driving methods, such as a scanning-impulsive method, a sequential scanning method, a localized dimming method, etc.
However, light properties of the LED, such as color temperature, or brightness, etc., are varied according to hours of usage and the surrounding temperature. Thus, the uniformity (or white color balancing) of the white light emitted from the LED is deteriorated.
Recently, a color feedback system (CFS) using an optical sensor has been developed in order to compensate the uniformity of the white light.
The CFS controls a driving current applied to the LED based on a light amount from the entire LED array, so that the LED emits a desired light in response to the controlled driving current.
However, in order to apply the CFS to the LED backlight operated in the localized dimming method that separately controls the brightness of the display panel according to divided regions of the display panel, an optical sensor needs to be installed in each region of the display panel, so that a manufacturing cost of the display panel increases. Also, a light interference from adjacent regions needs to be prevented in order to accurately detect the light amount of each region. Accordingly, the CFS is difficult to be applied to the LED backlight operating in the localized dimming method.